Electric insulator



' Dec. 30,1924. 1,520,984

F. H. THOMAS ELECTRIC INSULATOR Original Filed Aug. 29, 1213 /JLA/LAA' At). v /Lul ATTORNEY Patented Dec. 30, 1924.

.UNITED STATE-s PATENTHoFF-lca.

-PIERCY H. THOMAS, F PPER MONTCLAIR. NEW JERSEY, ASSIGNOR TO WESTING- HOUSE ELECTRIC MANUFACTURING COMIEIANY.` A CORPORATION OF PENNSYL- VANIA.

ELECTRIC INSULATOR.

Original application illed August 29, 1918, Serial No. 787,243. Divided and this application led February 8, 1918.

of Essex, State'of New Jersey, have invented certain new and useful Improvements in Electric Insulators, of which the following is a' specification.

Iy invention relates to electric insulators of the class particularly adapted for high tension electric lines although it may be used as well in connection with other electrical uses` than with high tension. It is desil-ed, among other objects, to provide an insulator of the suspension type which is adapted .g for extra-high tension service.

Other objects, advantages and purposes offthis type ofinsulator are set forth at greater length' in the specification of my Patent No. 1,273,015, issued July 16, 1918, to which reference is hereby expressly made.

In the following I have described, 'in connection with the accompanying drawings, different forms of devices illustrating the application of the principles ot' my invention.

. In the drawings Fig. l is a vertical sectional view of an insulator showing one wayof practicing my invention; Fig. 2 is a top plan view of the device shown in Fig. 1 on a larger scale with the rain guard removed; Fig. 3 is a sectional view, partly broken away, of the parts shown in Fig. 2 along the linclG-H; and Fig. 4 is a vertical sectional view of a modification of the type of insulator shown in Fig. 1. Similar numerals ofreference indicate similar parts throughout the several views.

In constructing the main body of my insulator I prefer to use a material having Ya lighdieleetric quality and onev capable of being obtained of high quality, and of ,great uniformity. Porcelain or glassv are suitable materials for the purpose. In ce- 45menting certain of the parts together any -.-suitable cement may be used and either g.Portland cement or cement made of litharge anfdfglycerine will give good satisfaction. p-ggflliemet-al parts of the insulatormay be 5.0 of any su'itable metal giving the desired gjmeehanical strength and malleable cast iron uor steel forgings are suitable for the pur posc. The rainguards which are adapted -92 of dielectric `materia1.

Serial No. 215,972.

to improve the electrical eiliciency of insulator and to control the distribution ofthe electrical field may bc of any suitable nmter'ial such as galvanized iron.

Figs. 1,-2 and l show an insulator cumprising a c vlinder 83 of dielectric material provided with circular flanges Sel-8l and a bridge 85 separating the two ends of the cylinder from each other. Each 'end-of the cylinder is )rovided with recesses 86 arranged eircum erentially (Fig. 2) of the respective ends of the cylinder. The cylinder at each side of recesses 86 is flared outwardly to form strengthened wall for the recesses 86. 87` are metal cap pieces carrying pins 88 adapted 'to be cemented in recesses 86. Rain guards 89 are preferably integral with caps 87. The periphery of each rain guard 89 isfprovided with a rounded edgeY asshown. Rings 90 are carrieti by the'cap pieces`87. This form provides a large number of small points of application of strain to thefinsulating material. which relieve the lattermechanically and at the same time is simple and economical to construct.

Fig. 4 shows an insulator 'comprising a plurality of cylinders of dielectric material. cylinders 91-91 being similar to cach other and each closed at one end .by a bridge The connection between the cap pieces87 and the cylinders 91 is somewhat similar to that described in connection with the insulator shown in Fig'. 1.v Cylinders 91 and the intermediate cylinder 93 are joined togctherby pins remented in'recesses at the adjacent ends of said cylinders. Opposite the recesses formed to receive the connecting pins the respectivecylinders are flared outwardly as shown at 494: and also provided with ribs 95. The pur se of the flared out portions and of the ribs 95 is to strengthen the di electric material opposite said recesses. The

caps 87 are' wnnected'to the respective ends.

of the cylinders 91 by. means of pins 96 the lower ends of which are cemented in the reeessesBG in the ends' of the cylinders while the upper ends are provided with heads 97 resting on washers 98 fof any suitable material such as asbestos,'leather lead',"'et,'c.' the ShanksV of the pins 'having 'a slight play fui pcrforationsljthrough the lil() l im cap piec's 87, the cap pieces being provided I to any particular type of construction, the

forms shown being simply illustrative of various ways of carrying out the principles of my broad idea.

I claim:

1. An insulator comprising a body meniber of dielectric material having a plurality of laterally spaced symmetrically disposed longitudinal recesses at one end, said body member being of greater transverse area adjacent to said recesses than at an intermediate ortion of the body member to comensate or the dielectric material removed rom the recesses, and a longitudinal tension member secured in position in each of said recesses.

2. An insulator comprisin a body ineinber of vitreous materialI having a plurality of laterally spaced symmetrically disposed longitudinal recesses atone end, said body member being flared outwardly adjacent to said recesses to increase' the transverse area thereof and to thereby compensate for the loss of the dielectric and mechanical strength of the material removed from the recesses, and longitudinal tension members secured in position in said recesses.

3. An insulator, comprising a plurality of units of dielectric material arranged end to end and each having a plura ity of spaced circumferentially disposed recesses at each end,- metallic tension members secured in position in said recesses for rigidly connecting said units to form a compound unit, 1a ca piece arranged at each end of said comp'oun unit, and a plurality of metallic members secured in the outer end recesses of the end units for securing lsaid cap pieces in place, the dielectric material, being thicker adjacent to the points of attachment of the metallic members to compensate for loss of dielectric and mechanical strength in the material removed from said recesses.

4. An insulator, comprising a'body portion of dielectric .material,-1 cap'pieces at the respective ends, a plurality of metallic tension members at each end of the'insulator secured in recesses in said body poi-tion and serving to secure the cap-pieces in place,

and a rib on the dielectric material adjacent to each of said recesses.

5. In a tension insulator, a body portion of brittle material having end recesses, a cap piece vat each end of the body portion, a plurality of metallic members at each eiid secured in the recesses in the body portion and engaging the cap pieces, and means in in the cap-pieces for looselyv taking the load of said metallic .members on said cap pieces.

whereby freedom for expansion and deformation is secured.

6. In a line insulator in which :i tension Vload is transmitted by means of vitreous termediate portion thereof and liaving'gi.

pluralit pf equally circumferentially spaced ongitu inal recesses between said Surfin-es and a plurality of longitudinal tension niembers secured in position in said recesses.

8. -An insulator com rising a body portion of dielectric material, cap pieces at the respective ends thereof and a plurality of metallic members at each end of the body portion secured in recesses in said body portion and serving to secure the cap pieces in place, the dielectric material being'shaped adjacent to said recesses to compensate for loss of dielectric and mechanical strength in the material removed from said recesses.

In testimony whereof I have signed this specification.

PERCY H. THOMAS. Witness:

GEORGE F. WILSON. 

